LIFE SCIENCES P1 Prep 2017 QP Final · Title: Microsoft Word - LIFE SCIENCES P1 Prep 2017 QP...

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LIFE SCIENCES P1

PREPARATORY EXAMINATION

SEPTEMBER 2017

Education

KwaZulu-Natal Department of Education REPUBLIC OF SOUTH AFRICA

NATIONAL SENIOR CERTIFICATE

GRADE 12

Life Sciences/P1 2 Preparatory Examination September 2017 NSC

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INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Answer ALL the questions. Write ALL the answers in the ANSWER BOOK. Start the answers to EACH question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Make ALL drawings in pencil and label them in blue or black ink. Draw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. Do NOT use graph paper. You must use a non-programmable calculator, protractor and a compass, where necessary. Write neatly and legibly.



SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions.

Choose the correct answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.10) in your ANSWER BOOK, for example 1.1.11 D.

1.1.1 The developing foetus is well protected from mechanical damage

in the mother’s uterus by the …

A

B C D

amniotic fluid. placenta. umbilical cord. chorionic villi.

1.1.2 Which ONE of the following represents correct functions of the

cerebrum and medulla oblongata?

CEREBRUM MEDULLA OBLONGATA A Controls involuntary actions Controls voluntary actions B Controls voluntary actions Controls involuntary actions C Controls and co-ordinates

voluntary actions Co-ordinates voluntary actions

D Controls involuntary actions Co-ordinates voluntary actions 1.1.3 In altricial development, young hatchlings are … A

B C D

unable to feed themselves soon after hatching. able to move around freely soon after hatching. completely independent of their parents after hatching. well developed when they hatch.

1.1.4 A function of the tympanic membrane and the oval window is to … A

B C D

equalize pressure between the outer and middle ear. concentrate sound waves onto a smaller surface area to amplify sound. transmit sound impulses to the brain to maintain balance. convert sound waves into nervous impulses.



1.1.5 A group of Grade 12 learners carried out an investigation to

determine the effect of gibberellins on the germination of seeds.

Which ONE of the following is a CORRECT conclusion for the

above investigation?

A

B C D

Gibberellins show a greater increase in the rate of germination of seeds than water Water shows a greater increase in the rate of germination of seeds than gibberellins There is no difference in the rate of germination of seeds placed in gibberellins and water Gibberellins decrease the rate of germination of seeds

1.1.6 The table below provides the insulin and glucagon levels in the

blood of a person over a period of three hours.

TIME

(mins) GLUCAGON

CONCENTRATION (mg/ml)

INSULIN CONCENTRATION

(mg/ml) 0 115 84

30 113 81 60 125 80 90 100 129

120 90 110 150 93 104 180 89 92

The changes in the level of hormones indicate that the person ate

a meal in the period …

A

B C D

0 - 60 mins. 60 - 90 mins. 90 - 120 mins. 120 -150 mins.

0102030405060708090

100

0 4 8 12 16 20

Ger

min

atio

n (%

)

Time (days)

Percentage germination of seeds in gibberellin solution and water over time

Gibberellin

Water



02468

101214

0 5 10 15 20 25 30Dis

solv

ed o

xyge

n (g

/L)

Temperature (degrees 0C)

Effect of temperature on the dissolved oxygen concentration in water

QUESTIONS 1.1.7 AND 1.1.8 REFER TO THE GRAPH AND THE TABLE BELOW.

Table of oxygen requirements of different organisms in a river 1.1.7 Thermal pollution causes the level of dissolved oxygen in the water

to …

A

B C D

remain unchanged. increase and then decrease. increase. decrease.

1.1.8 Due to the release of water from a factory, the temperature of the

water in a nearby stream is 30°C. Two organisms that are likely to be found living in the stream are …

A

B C D

striped bass and blue crab. worms and hard clam. worms and spot fish. yellow perch and spot fish.

Animal Striped Bass

Shad Yellow perch

Clams Blue Crab

Spot fish

Worms

Minimum oxygen requirements (mg/L)

6 5 5 4 3 2 1



0

2

4

6

8

10

0 0,1 0,2 0,3 0,4 0,5Dia

met

er o

f pup

il (m

m)

Time (seconds)

Changes in the size of the pupil diameter over time due to different light conditions

1.1.9 The diagram below shows the changes in the diameter of the pupil

over time while exposed to different light conditions.

During which period of time was the person exposed to bright light? A

B C D

0,1 to 0,4 sec 0,1 to 0,2 sec 0.2 to 0,4 sec 0,4 to 0,5 sec

1.1.10 An example of geotropism is the growth of the …

A B C D

stem towards gravity. root away from light. stem towards light. root towards gravity .

10 x 2 (20)



1.2 Give the correct biological term for each of the following descriptions.

Write only the term next to the question number (1.2.1 to 1.2.8) in the ANSWER BOOK.

1.2.1

1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.2.7 1.2.8

Failure of chromosomes to separate during meiosis The structure that provides nutrients to the developing embryo in oviparous organisms A growth response to gravity in plants An egg in which the embryo is protected by a shell The blood vessel that transports oxygen and dissolved food to the foetus Temporary storage site in a male for sperm cells The gland that secretes prolactin The system of the body composed of glands that secrete hormones responsible for chemical co-ordination

(8)

1.3 Indicate whether each of the descriptions in COLUMN I applies to A ONLY,

B ONLY, BOTH A AND B or NONE of the items in COLUMN II. Write A only, B only, both A and B or none next to the question number (1.3.1 to 1.3.3) in the ANSWER BOOK.

COLUMN I COLUMN II

(6)

1.3.1 Used to correct hearing problems caused by accumulated fluid in the middle ear

A: B:

Cochlear implant Grommet

1.3.2 Receptors for hearing A: B:

Rods Cones

1.3.3 The young develop inside the mothers body and are then born ‘alive’

A: B:

Ovoviviparous Viviparous

(3 x 2)



1.4 The diagram below shows some parts of the eye. Give the LETTER and NAME of the part that:

1.4.1 1.4.2 1.4.3

Contracts when looking at an object that is moving closer Is affected when a person has cataracts Regulates the size of the pupil

(2) (2) (2) (6)

Life Sciences/P2 8 KZN 2017 NSC


1.4 The diagram below shows some parts of the eye. Give the LETTER and NAME of the part that:

1.4.1 1.4.2 1.4.3

Contracts when looking at an object that is moving closer Is affected when a person has cataracts Regulates the size of the pupil

(2) (2) (2) (6)

A

B

C

D

E

F

G



1.5 The diagrams below show phases of meiosis in an animal cell.

1.5.1

1.5.2 1.5.3 1.5.4 1.5.5

Identify part: (a) A (b) C (c) E Give the FUNCTION of: (a) B (b) D (c) F Name TWO processes that are visible in the diagrams that result in genetic variation. How many chromatids will be present in each cell formed at the end of meiosis I? Name the phase shown in Diagram 1.

(1) (1) (1) (1) (1) (1) (2) (1) (1)

(10) TOTAL SECTION A: 50

Diagram 1 Diagram 2

A

B

C

D

E

F



SECTION B QUESTION 2 2.1 Water shortages in Cape Town have reached crisis levels.

If you were the Minister of Water Affairs, explain THREE strategies you could

use to ensure that the city of Cape Town copes with the water crisis.

(6)

2.2.1

2.2.2 2.2.3 2.2.4 2.2.5

Differentiate between a reflex action and a reflex arc. Tabulate TWO differences in structure between neuron A and B. Describe the reflex action that occurs as represented in the diagram. Explain what would happen if neuron A was damaged at point X. Explain how multiple sclerosis may result in the poor functioning of reflex arcs.

(2) (5) (5) (2) (2)

(16)

2.2 The diagram below represents a human reflex arc.

X

A

B



2.3. A tubal ligation is a surgical procedure in which a woman’s Fallopian tubes are

clamped and blocked. Mpume underwent this procedure to prevent pregnancy.

After many years, Mpume decided to have children but was advised that it was dangerous to reverse the tubal ligation. It was recommended that she try in vitro fertilisation (IVF) instead. She was given hormone supplements before the IVF was performed. The diagram below is a representation of how the IVF procedure was done.

2.3.1

2.3.2 2.3.3 2.3.4 2.3.5 2.3.6

Identify TWO hormones that were likely to be present in the hormone supplement given to Mpume.

Why is it not necessary for the hormone supplement to contain progesterone? How does a tubal ligation prevent a pregnancy? Describe the events that take place after fertilisation in the test tube until implantation occurs in the uterus. Describe the negative feedback mechanism between FSH and progesterone as it would occur in Mpume’s body during pregnancy. When Mpume falls pregnant, what will happen to the:

(a) Corpus luteum (b) Endometrium

(2) (2) (3) (6) (3) (1) (1)

(18) [40]

Ovum

Sperm Morula



05

10152025303540

Kwa-Zulu Natal

Western Cape

Eastern Cape

GautengPerc

enta

ge o

f pop

ulat

ions

af

fect

ed b

y fo

od in

secu

rity

Provinces in South Africa

Percentages of populations affected by food insecurity in some provinces in South Africa

1990's2000's

QUESTION 3 3.1 Gametogenesis occurs in males and females.

3.1.1 3.1.2 3.1.3

Describe the process of spermatogenesis. State ONE way in which the process of oogenesis is different from spermatogenesis. Explain why the testes in males are situated outside the body cavity.

(4) (2) (2) (8)

3.2 The graph below shows the percentage of populations affected by food

insecurity in some provinces in South Africa.

3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.2.7

Define food security. Name ONE province in which food insecurity has increased. List TWO factors that could have caused the increase in food insecurity in the province named in QUESTION 3.2.2. What percentage of the population in the Eastern Cape was food secure in the 1990’s? Show ALL working. Explain ONE way in which pesticides could decrease food security. Explain TWO ways in which genetically modified foods could increase food security. What conclusion can be made about the food security in Kwa-Zulu Natal from the graph provided.

(2) (1) (2) (2) (2) (4) (2)

(15)



3.3 An investigation was carried out as to determine the effect of adrenalin on

heart rate. The procedure was as follows: • The resting heart rate of three different men (A, B and C) was determined. • Each man was injected with the same amount of adrenalin. • After the injection each man’s heart rate was measured after 5 minutes.

The results of the investigation are provided in the table below.

CONDITION MAN A

MAN B

MAN C

Resting heart rate 80 85 92 Heart rate after the injection was given

115 98 120

3.3.1 3.3.2 3.3.3

State TWO ways in which the investigators increased the validity of the investigation. What served as a ‘control’ in this investigation? Explain how the effect of adrenalin on heart rate shown in the results is of benefit to a person in a dangerous situation.

(2) (1) (3)

(6) 3.4 Describe how the human body regulates the salt level in blood when it

decreases below normal.

(5)



3.5 The following investigation was performed to demonstrate one of the effects

of auxins. - Plant I had the top removed and replaced with a block of plain jelly. - Plant II had the top removed and replaced with a block of jelly containing

auxins. - Both plants were watered well and left in sunlight.

The jelly is able to allow auxins in it to diffuse into the plant.

The results of the experiment are shown below.

3.5.1 3.5.2 3.5.3 3.5.4

State which phenomenon is being investigated. Describe ONE change in appearance of Plant I after five days. Explain how the change in Plant I was brought about. State ONE way in which the reliability of the above investigation can be improved.

(1) (1) (3) (1)

(6) [40] TOTAL SECTION B: 80

Plant I Plant II Plant I Plant II Start of the investigation After 5 days

Plain jelly Jelly with auxins



SECTION C QUESTION 4

Kagiso Rabada, a South African cricket player, bowls during a cricket match on a hot day. Describe how Rabada’s temperature was lowered on the hot day, how he maintained his balance and equilibrium during his bowling and the role of hormones in maintaining his energy levels.

Content: (17) Synthesis (3)

(20) NOTE: NO marks will be awarded for answers in the form of tables, flow charts or

diagrams.

TOTAL SECTION C:

RAND TOTAL: 20

15

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